Scouting Soybean for Insect Pests

I began work as a field crop entomologist at the University of Illinois at Urbana-Champaign (UIUC) in September 2017, after having worked in a similar role for the University of Arkansas Cooperative Extension Service since 2014. My focus is on agronomic crops, including soybeans.

The variability of insect pest pressure in soybeans is striking, not just from region to region but from field to field. While the likelihood of many insect problems can be predicted due to field history or cultural practices, populations vary dramatically due to weather, natural enemies and other factors. Year-to-year variability in these complex factors can lead to dramatic shifts in insect populations. In addition, the movement behavior of many pests can be complex to the point of appearing random, causing one field to be infested at damaging levels while nearby fields are essentially “clean.” This year-to-year and field-to-field variability is why scouting is so critical to understanding what management actions should be taken in a given field.

As much as I would like to see a sweep-net running through every field in Illinois in 2018, thorough scouting is a tough sell for many producers in the state given the size and complexity of their operations. However, there are some general ways that you can guide sampling efforts to identify fields that need attention:

Know pests that are favored by certain conditions: Dectes stem borers are more common in areas with reduced tillage and continuous soybeans. Slugs (note: not an insect) can cause problems when residue and moisture are high. Spider mites (also not an insect) are much more likely under drought stress. These are just a few examples; most (if not all) pests have certain practices or environmental characteristics that make damaging infestations more likely.

Pay attention to field history: The importance of field history varies from species to species; however, keep notes from year to year to identify trends and whether you routinely see a pest at problem levels in certain fields (especially soil-dwelling insects like wireworms).

Stay up-to-date on what is happening in your area during the season: Every season is different, and there are many sources of information available to keep you informed. Blogs (including ILSoyAdvisor), newsletters, field days, agronomists and neighbors can all keep you up-to-date on what others are seeing in your area. Just remember that infestations are variable and this is a supplement to scouting, not a replacement.

I look forward to working with producers and crop advisors in Illinois to help develop and improve management practices for insect pests. Please contact me at nseiter@illinois.edu if you have any burning questions, areas you would like to see investigated related to soybean insect management, or just observations on insect management trends in Illinois. In addition, updates will be provided through Twitter about insect management observations during the field season.

As a new faculty member and entomologist in Illinois I will be seeking input frequently to help guide my program in directions I hope will provide valuable and relevant solutions to producers.